A, gold (Gold) is the chemical element gold (Au) in the form of a single mass, is a soft, gold-colored, corrosion-resistant precious metal. Gold is one of the rarer, more precious and extremely valued metals. Internationally, gold is generally measured in ounces, and in ancient China it was measured in "two" as the unit of gold, making it a very important metal. It is not only a special currency used for reserve and investment, but also an important material for jewelry industry, electronics industry, modern communication, aerospace and aviation industry and other sectors. The chemical symbol for gold is Au, and the financial English code is XAU or GOLD. the name Au comes from a story about Aurora, the goddess of dawn in Roman mythology, which means shining dawn. As of October 12, 2021, the price of gold is $1,760 per ounce.
Two, identify adulteration
1, whether the gold has white highlights with material shears will be gold bars or gold jewelry cut, with a magnifying glass to observe its cut, if you see a white highlights, due to the gold and iridium can not be fused together, then it is said that the gold is adulterated with iridium.
2, specific gravity. First use the balance to measure the weight of a pure gold bar, then put the gold bar into the measuring cup, pouring water to submerge the gold bar. Then put the tested gold bar into the measuring cup, observe the water scale is rising or falling, as long as the change, that is, the gold bar is not pure gold. But if it is gold jewelry, this method is not applicable, because there is air inside the gold jewelry.
3, real gold is not afraid of fire. Put the gold bar or gold jewelry on the fire for a while, observe the changes. As iridium will be combined with the oxygen in the air oxidation reaction, so the purity of the gold bars will not be enough to turn gray; and pure gold after the fire baked color will be red shiny. However, this method may have some damage to the jewelry.